Mold for vulcanizing rubber to leather



1 and exhaust pipes are provided for ad mission UNITED STATES PATENT OFFICE.

GEORGE F. BUTTERFIELD, OF STONEHAM, MASSACHUSETTS.

MOLD FOR VULCANIZING RUBBER TO LEATHER.

SPECIFICATION forming partvof Letters Patent. No. 349,690, dated September 28, 18126.

Application filed December Q1, 1885.

To all whom it may concern.-

Beit known that I, GEORGE F. BUTTER- FIELD, ot' Stoneham, in the county of Middle# sex and State of llIassachusetts, have invented certain new and useful Improvements in Molds for Vulcanizing Rubber to Leather, of which the following', taken in connection with the accompanying drawings, is a specification. y

This invention relates to molds for vulcanizing rubber upon leather surfaces, and in its present application is especially designed to hold a shoe or boot in position and a quantity 0f rubber compound in a sole-shaped recess in contact with the leather sole, so that the rubber may be vulcanized directly thereon, as stated in -my application No. 173,972, filed August 10, 1885. f

My improved mold is peculiar, in that one of its members has asuitably-shaped recess in its outer face and an inclosed steanrchamber adjacent to such recess, while a cavity is formed in the other portion of the mold or between the two parts of which such portion isl co1nposed to receive the shoe or other article and hold it rmly in position with its sole directly in contact with the portion of rubber compound contained in said recess. Steam inlet and escape of steam, and provision is made for a water-current through the chamber when desired. The cap may be made of or lined with comparatively non-conducting material, so that the upper leather shall not be overheated..

In the drawings, Figure l is a vertical section on line xx, Fig. 2, through one of my iniproved molds containing a shoe; and Fig. 2 is a top plan of the lower section of the mold, showing the sole-shaped recess and the guide pins or bolts. Fig. 3 is a transverse section on line y y, Fig. 1 but showing the mold with a pulp-lined cap.

'A is the body of the mold, having the steanichamber B within it, and provided with the steam-inlet pipe C and exhaust-pipe D, in order to insure suitable pressure and current of steam. These pipes are furnished with suitable valves, E, to regulate or cut oft the steam-current. The pipes may have branches, as F, titted with stop-cocks G, through which ASerial No. 186,313. (No model.)

mold is a recess, 1t, shaped to correspond with the i'orm desired in the completed sole orother article being formed. The drawings show in Fig. 2 a sole-shaped recess, and in Fig. 1 a

shoe is represented covering such recess, and

a body ot' rubber filling the same and forming the rubber sole S in immediate contact with the leather sole T of the shoe, to which it is Vpermanently secured by Vulcanizatiou.

A further peculiarity of the mold is the cavity in its upper portion or cap V, to receive the body of the shoe. This cavity may be open at the top to allow the 'shoe U to protrude, as shown, and will ordinarily constitute the space between the two parts oi' the cap, which are preferably made to separate laterally at a central longitudinal line, as indicated in.

Fig. l, where one half oi' the cap is removed. I provide guide pins or bolts WV, and nuts or equivalent fastening-s to secure the parts ot' the cap to each other and the cap to the body A, so as to resist the strain due to 'the expansion oi' the rubber in vuleanizing.

The cap and the mold-body may be held in close contact by use of a press or any suitable clamping devices. Y

Another feature of my invention, illustrated in Fig. 3, is designed to obviate overheating of the upper leather of the shoe, to secure cheapness oi construction ci the cap, and a better iit between the edges oi' the shoe and the cap. This feature consists in making the mold-cap, or the part of it which comes in contact with the upper leather, of non-conducting material and of a material such as paperpulp P or a compound thereof, which may be applied in a plastic state over a shoe held in the mold and hardened under pressure, so as to conform internally to the exterior oif' the shoe near its sole edges.

The mold-cap may be a metallic shell with a pulp lining molded withinit the conversein shape of the shoe to be treated, so as to secure the strengthof the shell and the 'lit and nonconducting quality of the lining. i I do not .limit myself to this forni of cap, since I am ICO accustomed to malte them also, as in Fig. '1, of cast metal, formed by first molding a plaster pattern from the shoe direct the reverse of the shoe land then casting the cap in the sand molded as usual from this pattern.

I am aware that in the manufacture of rubber boots, &c.,- molds have been used having steam chambers or jackets surrounding the sole, the upper, and the leg of the boot, so as to inclose the entire boot Within the stea1nspaces. Such apparatus would not be suitable for my purpose, since I apply the steam-heat only to the rubber sole and use the mold-cap simply as a clamp to hold the shoe in proper relation to the recess containing the rubber sole, so that the rubber, by the heat and presslll'G, affixed toetheleathcr. Ikeep the cap or clamp as cool as possible, to avoid injury to the leather.

of my mold-body A, and notonly shapes the bottom but also the edges of the rubber sole.

I cla-im as my inventionl. The described nlold for vulcanizing rubsball Ybecome eured and permanently Y The recess 'R is sunken in the surface ing as clamps, to hold the shoe to the mold l body A, With its sole T covering said recess R, substantially as set forth.

2. The hollow niold-body A, provided with steam-connections, as described, and having the surface recess It, in combination with the recessed cap V, having an inner surface of non-eonducting material, substantially as and for the purpose set forth..

In testimony whereof I have signed vmy naine to this specification, in the presence of two subscribing witnesses, on this 26th day ol' October, A. D. 1885.

. GEORGE l?. BUTTERFIELD.

A\'V i tn esses:

A. H. SrENrmn, (I. G. KEYES. 

